[Unclenick]

IMR 4895 does quite well with heavier bullets, like the 80 grain match bullets, but is inefficient with light ones. With a 55 grain bullet you can get the same velocity at only 5% higher peak pressure using almost 20% less IMR 4198 by weight. That translates to less muzzle blast, which is usually helpful to accuracy. 4895 is well known for shooting better at lower pressures than most rifle powders can, though, so YMMV if you don't mind the waste. IMR 4198 is a very good accuracy powder in both .222 and .223 Remington.

Believe it or not, a 1:9 twist is actually close to ideal for the 0.9" long 69 grain Sierra MatchKings, producing a calculated (Don Miller's formula) gyroscopic stability factor of 1.6 at 2500 fps MV. That's right in the range of 1.4 to 1.7 usually cited as optimal for highest accuracy. This is under Army standard meteorological conditions, and in very cold weather, the stability will be decreased by the more dense air.